Consent to treatment

Consent to treatment is the principle that a person must give their permission before they receive any type of medical treatment or examination. This must be done on the basis of a preliminary explanation by a clinician.

Consent is required from a patient regardless of the intervention – from a physical examination to organ donation.

The principle of consent is an important part of medical ethics and the international human rights law.

It can be given:

Verbally – for example, by saying they are happy to have an X-ray.

In writing – for example, by signing a consent form for surgery.

Patients may passively allow treatment to take place –for example, by holding out an arm to show they are happy to have a blood test. However, since the capacity to consent has not been tested, and the benefits and risks have not been explained, this is not the same as consent (see below).

"Capacity" means the ability to use and understand information to make a decision, and communicate any decision made.

Defining consent

For consent to be valid, it must be voluntary and informed, and the person consenting must have the capacity to make the decision. These terms are explained below:

Voluntary– the decision to either consent or not to consent to treatment must be made by the person themselves, and must not be influenced by pressure from medical staff, friends or family.

Informed– the person must be given all of the information in terms of what the treatment involves, including the benefits and risks, whether there are reasonable alternative treatments and what will happen if treatment does not go ahead.

Capacity– the person must be capable of giving consent, which means they understand the information given to them, and they can use it to make an informed decision.

If an adult has the capacity to make a voluntary and informed decision to consent to or refuse a particular treatment, their decision must be respected. This still stands even if refusing treatment would result in their death, or the death of their unborn child.

If a person does not have the capacity to make a decision about their treatment, the healthcare professionals treating them can go ahead and give treatment if they believe it is in the person’s best interests. However, the clinicians must take reasonable steps to seek advice from the patient’s friends or relatives before making these decisions.

How to give consent

Consent should be given to the healthcare professional directly responsible for the person's current treatment, such as the nurse arranging a blood test, the GP prescribing new medication or the surgeon planning an operation.

If someone is going to have a major medical procedure, such as an operation, their consent should ideally be obtained well in advance, so they have plenty of time to examine any information about the procedure and ask questions. If they change their mind at any point before the procedure, the person is entitled to withdraw their previous consent.

If someone with little or no chance of recovery requires treatment for the sole purpose of keeping them alive, and the person is unable to make a decision themselves, an agreement about continuing or stopping treatment will need to be reached between the healthcare professionals responsible for their care and the person's relatives and friends. Read more about consent and end of life issues.

When consent is not necessary

There are a few exceptions when treatment can go ahead without consent.

For example, it may not be necessary to obtain consent if:

Treatment is needed in an emergency, and the person is unable to give consent because they lack the capacity to do so.

When, during an operation, it becomes obvious that the person immediately requires an additional procedure to treat a life-threatening problem that was not included in their original consent.

A person with a severe mental health condition – such as schizophrenia, bipolar disorder or dementia– lacks the capacity to consent to the treatment of their mental health. However, in these cases, treatment for unrelated physical conditions still requires consent, which the patient may be able to provide, despite their mental illness.

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